bugger... i thought i had it bookmarked but i found it...
this is the one ive used in the past: http://funadvice.com/r/14njdon806u
a free video converter: http://funadvice.com/r/14njdheues3
ive used this one in the past and it does what it says on the tin.
but failing that ive used online converters too:
You could use a video converter.